1. Field of the Invention
The present invention generally relates to a sealed container which comprises a container and a container closure which is arranged to be repeatedly opened and closed on the body of the container.
2. Discussion of Relevant Information and Prior Art
It is known that sealed containers for foods, e.g., powdered milk or wax, require closures which can be repeatedly opened or closed. With such apparatus it is necessary, each time the container is used, that it be both opened and closed. Accordingly, conventional sealed containers have been developed in which the container body and the closure for the container are threadably and detachably engaged to each other.
Such sealed containers are inconvenient, however, particularly when the sealed container is relatively large in diameter, e.g., in the case of a powdered milk can or similar structure, because it is difficult for a user to use his fingers to grasp such a large container closure. Under such circumstances, a relatively large force is required to open and close the container; particularly when the hand of a user is small, it is difficult for the user to open and close the container.
Other types of container opening and closing arrangements have been proposed which are alternatives to the threaded type of closing arrangement discussed above. In one example of such prior art, as illustrated in FIGS. 4A and 4B of the present case, and as disclosed in Japanese Unexamined Utility Model Application Publication Nos. Sho/57-11749 and Sho/57-11750, a thin metallic plate material is formed into a container closure (c), the container closure having a downwardly depending peripheral wall portion (a) provided with an arcuate cut-out opening (b) which surrounds or defines an arcuate cut-out lower edge, extending in the form of an arc from a lower edge of peripheral wall portion (a) towards an upper surface of the wall portion. The closure is mounted at peripheral wall portion (a) to an outer surface of peripheral wall (f) of container body (e), which container body includes an outer peripheral ridge (d).
The type of sealed container described above is opened in a fashion such that, if a portion of top panel (g) of the container closure (c) which is located above cut-out opening (b) is pushed downwardly, as illustrated in both FIGS. 4A and 4B, the two lower edge or end portions (h), located along both sides of the arcuate cut-opening (b), will be in contact with ridge (d) of container body (e), and thus the two ridge points which contact end portions (h) will serve as fulcrums for the pivoting opening movement of the closure. By so functioning, an area of peripheral wall portion (a) of container closure (c), which includes the cut-out opening portion (b), will be moved downwardly at an angle, whereas a region of peripheral wall portion (a) of container closure (c) which is located on the side of the closure opposite to cut-out opening portion (b) will be moved upwardly and removed from container body (e). This motion is best illustrated in FIG. 4A, in which only the recessed portion remains on the container body.
These types of arrangements, however, are particularly useful for making large diameter sealed containers, e.g., powdered milk cans or similar structures, in which top panel portion (g) of container closure (c) is formed with a sufficiently large area making it necessary to provide a cut-out opening portion (b) along peripheral wall portion (a) of container closure (c) with a sufficiently large width or span between lower edge portions (h). In this structure, there is a problem when top panel portion (g) of container closure (c) is pushed downwardly along a region located directly above cut-out opening portion (b) in order to open the closure, insofar as the depressed region of top panel portion (g) will be bent or deformed downwardly; and as a result of this downward deformation, cut-out opening portion (b) of peripheral wall portion (a) will be undesirably widened in a substantially side-to-side fashion over the span between lower edges portions (h,h), which will prevent the opposed side portions of container closure (c) from being easily lifted and render it difficult to open the container closure. Further, if the cut-out opening portion (b) is too large, the pushing or depressing force acting on the area of the top panel portion (g) will cause lower edge portions (h,h) to move outwardly, so that these opposite edge portions located along both sides of cut-out opening portion (b) will be removed from ridge (d) of container body (e); in this fashion, the two spaced ridge points which are in contact with lower edge portions (h,h) will be prevented from serving as fulcrums and it will be impossible to open container closure (c).
Additionally, it is desirable to curl the entire circumference of the lower edge of peripheral wall portion (a) of the thin metallic plate material which comprises container closure (c) in order to prevent danger to users resulting from injuring their hands or fingers on the lower edge of the metal plate material. It is, however, extremely difficult to curl the arcuate lower edge of the closure which surrounds cut-out opening (b) in the prior art closures, so that an additional danger which is difficult to eliminate will remain.